1. Field of the Invention
This invention relates to locks, and more particularly to locks used for retaining and securing objects by means of cables, bolts or other shaft projections.
2. Background
Locks serving as shaft retainers have been available for a long time. A common practice for a shaft having an end with a transverse bored hole, is to connect a padlock through the hole in the shaft end. This is practical for applications where the shaft diameter is relatively large and can easily accommodate a padlock arm, but impractical for a small diameter shaft.
Cable shaft locking and retaining devices have also been used as far back as the mid 19th century period. Among the more recent cable retaining devices are those described by Smith in U.S. Pat. No. 5,517,835, Lyon et al in U.S. Pat. No. 3,987,653 and Joo in U.S. Pat. No. 4,099,394. Smith describes a device for use with a cable formed into two or more loops. A ferruled end of the cable is inserted in the device and one or more loops of the cable are also inserted in the device and pulled through. Turning a key lock in the device causes two or more wedge-shaped elements to grip the cable along its length inside the device, retaining the cable.
Lyon et al describe a device for locking a looped cable, One end of the cable is inserted and anchored to the device by a ring. The other end of the cable is passed through the device. The cable is clamped and partially deformed by turning a key lock that rotates a threaded shaft, activating a clamp around the cable. Joo describes storage reel for a cable which is hinged to a bicycle frame. In use, the cable is drawn around a post or other immovable object, and fastened to a projection on the bicycle, utilizing a padlock to lock it in place.
A recent example of a shaft projection retainer lock is that described by Stillwagon et al in U.S. Pat. No. 6,197,314. Stillwagon et al describe a device that includes the shaft projection and a key-turned lock that causes a sleeve or collar to grip the shaft projection. In this invention embodiment, the shaft projection may be fixed in a door or cabinet, or instead in the key-turned device with a collar-gripping portion fixed in a door to receive the projection. A later device by Stillwagon, U.S. Pat. No. 5,467,619 expands further on the above described second Stillwagon embodiment by incorporating a long, threaded shaft into the key-turned portion of the device. In the above described Stillwagon devices, the shaft projection must be particularly sized in length, stepped and/or threaded to fit its mating lock portion. This is because it is described as being part of the locking device. While useful for their described applications, the Stillwagon devices are not useful for retaining other shaft projections such as bolts, cable ends and the like.
In view of the foregoing, there is a need for a simple, universal locking device that can be applied to retain single shaft projections of various configurations.